What is the best underlay for a floating wood floor?

There are many different types of wood flooring, and floating wood flooring is one of the most popular. Once you've chosen this type of wood flooring for the advantages it offers, you need to choose the right underlay.
Your floating wood flooring is not laid directly on the floor of the room. It is laid on an underlay, which can provide sound insulation.
 Note that the underlay for a floating wood flooring is compulsory, and there are several models available, each with different characteristics. 
 So, which underlay is best suited to floating wood flooring?

How thick should the underlay ?

Sometimes, people assume that any thick or padded material (such as a rug) will make a good wood floor underlay. In reality, an underlay that is too thick will create too much space between the different parts of the floating floor, putting strain on the points where the strips meet. To put it simply, an overly thick underlay makes the wood floor too flexible and therefore weaker.
That's why you should choose the underlay for your floating floor with care. In general, a thickness of several millimetres is sufficient.

Choosing an underlay with the right level of insulation

The soundproofing properties of a wood floor underlay

People who have noisy neighbours living upstairs will be able to vouch for the fact that sound and vibrations are easily transmitted from one floor to another. Wood floor underlays are designed to reduce noise disturbance. This is what's called soundproofing and acoustic insulation.
Soundproofing refers to the prevention of noise transmission from the inside to the outside of a property.
In other words, a floating floor underlay is designed to reduce the transmission of impacts (footsteps, falling objects, washing machine vibrations) between the wood and the floor. Your insulation requirements will differ depending on your property, the neighbouring properties and the room where your wood floor is installed.

Thermal insulation

This criterion needs to be studied closely if you have underfloor heating. The thermal resistance of the underlay must be as low as possible. 

Choosing a suitable floating wood floor underlay for your chosen room

Underlay is designed to protect the wood of your floating floor as much as possible.

Moisture can vary considerably from one room to the next, depending on each one's location within the property, the amount of sunlight received and how well ventilated the space is. Any temperature fluctuations and the transfer of heat (or lack of it) between the wood and the floor can lead to problems with moisture.

Do I need a vapour barrier for my floating floor underlay?

To a certain extent, the underlay will protect your floating wood flooring from rising damp. 

However, on at-risk subfloors, you will need to install a barrier to prevent rising damp.
On the other hand, on wooden subfloors, the underlay should be as breathable as possible.

The different types of floating wood floor underlays

Polyethylene (PE) foam underlay – the most economic underlay

The most common type of underlay, polyethylene foam is cheap, easy to install and comes in ready-to-use rolls. It is thinner than other types of underlay and therefore less insulating:

  • It can be laid over underfloor heating thanks to its low thermal resistance;
  • It is breathable enough to be used on wooden floors;
  • It should be complemented by a moisture barrier on at-risk substrates.

This is Panaget's Isol 20 underlay.

Polyethylene underlay with polyane: the high-performance underlay

Ready-to-install in roll form, polyethylene underlay with polyane (Isol 30) offers a number of advantages. 

  • Its soundproofing performance meets current standards;
  • The integrated 200 micron polyane provides a barrier against rising damp;

These two advantages make it incompatible with wooden subfloors and underfloor heating.

Cork and rubber underlay: the most complete solution

Ready to install in roll form, Isol 40 cork and rubber underlay is a great environmentally-friendly alternative to industrial underlay. 

  • Its 2 mm thickness means you can reduce the height of the underlay; 
  • It can be laid floating or glued down; 
  • Its soundproofing performance complies with current standards;
  • It provides excellent acoustic insulation by absorbing impact vibrations;
  • It is impact resistant;
  • It is environmentally friendly, made from recycled cork and rubber; 
  • It is breathable enough to be used on wooden floors;
  • It should be complemented by a moisture barrier on at-risk surfaces.


If you have any questions, the Panaget team is always available. Get in touch with our advisers to find out more.